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kernel-ark/fs
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David Howells 1bccf513ac FS-Cache: Fix lock misorder in fscache_write_op() 
FS-Cache has two structs internally for keeping track of the internal state of
a cached file: the fscache_cookie struct, which represents the netfs's state,
and fscache_object struct, which represents the cache's state.  Each has a
pointer that points to the other (when both are in existence), and each has a
spinlock for pointer maintenance.

Since netfs operations approach these structures from the cookie side, they get
the cookie lock first, then the object lock.  Cache operations, on the other
hand, approach from the object side, and get the object lock first.  It is not
then permitted for a cache operation to get the cookie lock whilst it is
holding the object lock lest deadlock occur; instead, it must do one of two
things:

 (1) increment the cookie usage counter, drop the object lock and then get both
     locks in order, or

 (2) simply hold the object lock as certain parts of the cookie may not be
     altered whilst the object lock is held.

It is also not permitted to follow either pointer without holding the lock at
the end you start with.  To break the pointers between the cookie and the
object, both locks must be held.

fscache_write_op(), however, violates the locking rules: It attempts to get the
cookie lock without (a) checking that the cookie pointer is a valid pointer,
and (b) holding the object lock to protect the cookie pointer whilst it follows
it.  This is so that it can access the pending page store tree without
interference from __fscache_write_page().

This is fixed by splitting the cookie lock, such that the page store tracking
tree is protected by its own lock, and checking that the cookie pointer is
non-NULL before we attempt to follow it whilst holding the object lock.

The new lock is subordinate to both the cookie lock and the object lock, and so
should be taken after those.

Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19 18:11:25 +00:00
..
9p 9p: fix readdir corner cases 2009-11-02 08:43:45 -06:00
adfs adfs: remove redundant test on unsigned 2009-09-24 07:21:05 -07:00
affs affs: add ->sync_fs 2009-06-11 21:36:14 -04:00
afs afs: remove cache.h 2009-10-01 16:11:16 -07:00
autofs trivial: remove unnecessary semicolons 2009-09-21 15:14:58 +02:00
autofs4 autofs4 - fix missed case when changing to use struct path 2009-08-31 17:44:05 -10:00
befs fs: Make unload_nls() NULL pointer safe 2009-09-24 07:47:42 -04:00
bfs headers: smp_lock.h redux 2009-07-12 12:22:34 -07:00
btrfs Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable 2009-11-11 13:38:59 -08:00
cachefiles FS-Cache: Allow the current state of all objects to be dumped 2009-11-19 18:11:04 +00:00
cifs cifs: clear server inode number flag while autodisabling 2009-11-16 15:24:03 +00:00
coda headers: remove sched.h from poll.h 2009-10-04 15:05:10 -07:00
configfs writeback: add name to backing_dev_info 2009-09-11 09:20:26 +02:00
cramfs
debugfs debugfs: use specified mode to possibly mark files read/write only 2009-06-15 21:30:28 -07:00
devpts Move magic numbers into magic.h 2009-09-23 07:39:28 -07:00
dlm dlm: fix socket fd translation 2009-09-30 12:19:44 -05:00
ecryptfs ima: ecryptfs fix imbalance message 2009-10-08 11:31:38 -05:00
efs get rid of BKL in fs/efs 2009-06-17 00:36:36 -04:00
exofs exofs: remove BKL from super operations 2009-09-24 07:47:38 -04:00
exportfs
ext2 Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 2009-09-24 07:53:22 -07:00
ext3 ext3: Wait for proper transaction commit on fsync 2009-11-11 15:22:49 +01:00
ext4 ext4: partial revert to fix double brelse WARNING() 2009-11-08 15:45:44 -05:00
fat Merge git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6 2009-09-30 09:31:14 -07:00
freevxfs headers: smp_lock.h redux 2009-07-12 12:22:34 -07:00
fscache FS-Cache: Fix lock misorder in fscache_write_op() 2009-11-19 18:11:25 +00:00
fuse fuse: invalidate target of rename 2009-11-04 10:24:52 +01:00
gfs2 SLOW_WORK: Wait for outstanding work items belonging to a module to clear 2009-11-19 18:10:23 +00:00
hfs hfs: fix oops on mount with corrupted btree extent records 2009-10-29 07:39:29 -07:00
hfsplus hfsplus: refuse to mount volumes larger than 2TB 2009-10-29 07:39:27 -07:00
hostfs hostfs: set maximum filesize in superblock for proper LFS support 2009-06-30 18:56:03 -07:00
hpfs headers: smp_lock.h redux 2009-07-12 12:22:34 -07:00
hppfs
hugetlbfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-09-24 08:32:11 -07:00
isofs fs: Make unload_nls() NULL pointer safe 2009-09-24 07:47:42 -04:00
jbd fs/jbd: Export log_start_commit to fix ext3 build. 2009-11-12 10:24:12 +01:00
jbd2 JBD/JBD2: free j_wbuf if journal init fails. 2009-11-11 15:24:14 +01:00
jffs2 Merge git://git.infradead.org/mtd-2.6 2009-09-23 10:07:49 -07:00
jfs fs: Make unload_nls() NULL pointer safe 2009-09-24 07:47:42 -04:00
lockd headers: utsname.h redux 2009-09-23 18:13:10 -07:00
minix V3 minixfs: add missing directory type checking 2009-09-23 07:39:57 -07:00
ncpfs const: mark struct vm_struct_operations 2009-09-27 11:39:25 -07:00
nfs NFSv4: The link() operation should return any delegation on the file 2009-10-26 08:09:46 -04:00
nfs_common
nfsd Fix memory corruption caused by nfsd readdir+ 2009-11-14 12:55:55 -08:00
nilfs2 nilfs2: deleted inconsistent comment in nilfs_load_inode_block() 2009-11-15 17:17:46 +09:00
nls Merge git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6 2009-09-30 09:31:14 -07:00
notify dnotify: ignore FS_EVENT_ON_CHILD 2009-10-20 18:02:33 -04:00
ntfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-09-24 08:32:11 -07:00
ocfs2 const: constify remaining file_operations 2009-10-01 16:11:11 -07:00
omfs const: constify remaining file_operations 2009-10-01 16:11:11 -07:00
openpromfs
partitions block: Seperate read and write statistics of in_flight requests v2 2009-10-06 20:16:55 +02:00
proc procfs: fix /proc/<pid>/stat stack pointer for kernel threads 2009-11-17 17:40:33 -08:00
qnx4 qnx4: remove write support 2009-09-23 07:39:30 -07:00
quota const: make struct super_block::s_qcop const 2009-09-22 07:17:24 -07:00
ramfs truncate: use new helpers 2009-09-24 08:41:47 -04:00
reiserfs const: make struct super_block::s_qcop const 2009-09-22 07:17:24 -07:00
romfs ROMFS: fix length used with romfs_dev_strnlen() function 2009-10-11 11:33:56 -07:00
smbfs fs: Make unload_nls() NULL pointer safe 2009-09-24 07:47:42 -04:00
squashfs const: mark remaining super_operations const 2009-09-22 07:17:24 -07:00
sysfs sysfs: Don't leak secdata when a sysfs_dirent is freed. 2009-11-05 08:19:18 +11:00
sysv get rid of BKL in fs/sysv 2009-06-17 00:36:37 -04:00
ubifs const: mark struct vm_struct_operations 2009-09-27 11:39:25 -07:00
udf udf: Fix possible corruption when close races with write 2009-09-14 19:13:01 +02:00
ufs ufs: sector_t cannot be negative 2009-06-18 13:03:46 -07:00
xfs xfs: copy li_lsn before dropping AIL lock 2009-11-17 10:26:49 -06:00
aio.c aio.c: move EXPORT* macros to line after function 2009-09-23 07:39:29 -07:00
anon_inodes.c headers: remove sched.h from poll.h 2009-10-04 15:05:10 -07:00
attr.c truncate: new helpers 2009-09-24 08:41:47 -04:00
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c fdpic: ignore the loader's PT_GNU_STACK when calculating the stack size 2009-09-24 07:21:02 -07:00
binfmt_elf.c elf: clean up fill_note_info() 2009-09-24 07:21:01 -07:00
binfmt_em86.c
binfmt_flat.c flat: use IS_ERR_VALUE() helper macro 2009-09-24 07:21:03 -07:00
binfmt_misc.c
binfmt_script.c
binfmt_som.c
bio-integrity.c block: Create bip slabs with embedded integrity vectors 2009-07-01 10:56:25 +02:00
bio.c Fix bio_alloc() and bio_kmalloc() documentation 2009-11-02 11:41:13 +01:00
block_dev.c block: use after free bug in __blkdev_get 2009-10-26 15:27:11 +01:00
buffer.c Merge branch 'writeback' of git://git.kernel.dk/linux-2.6-block 2009-09-25 09:27:30 -07:00
char_dev.c fs/char_dev.c: remove useless loop 2009-09-24 07:21:03 -07:00
compat_binfmt_elf.c
compat_ioctl.c fs: add missing compat_ptr handling for FS_IOC_RESVSP ioctl 2009-11-12 07:25:57 -08:00
compat.c x86, fs: Fix x86 procfs stack information for threads on 64-bit 2009-11-04 13:25:03 +01:00
dcache.c sched: Pull up the might_sleep() check into cond_resched() 2009-07-18 15:51:44 +02:00
dcookies.c
direct-io.c
drop_caches.c sysctl: remove "struct file *" argument of ->proc_handler 2009-09-24 07:21:04 -07:00
eventfd.c anonfd: split interface into file creation and install 2009-09-23 07:39:29 -07:00
eventpoll.c epoll: fix nested calls support 2009-06-18 13:03:41 -07:00
exec.c exec: setup_arg_pages() fails to return errors 2009-11-12 07:25:58 -08:00
fcntl.c fcntl: rename F_OWNER_GID to F_OWNER_PGRP 2009-11-17 17:40:33 -08:00
fifo.c
file_table.c sysctl: remove "struct file *" argument of ->proc_handler 2009-09-24 07:21:04 -07:00
file.c headers: remove sched.h from interrupt.h 2009-10-11 11:20:58 -07:00
filesystems.c
fs_struct.c
fs-writeback.c writeback: pass in super_block to bdi_start_writeback() 2009-09-26 00:10:40 +02:00
generic_acl.c
inode.c vfs: optimize touch_time() too 2009-09-24 07:47:27 -04:00
internal.h fs: fix overflow in sys_mount() for in-kernel calls 2009-09-24 08:40:15 -04:00
ioctl.c __generic_block_fiemap(): fix for files bigger than 4GB 2009-11-12 07:26:01 -08:00
ioprio.c
Kconfig powerpc: Cleanup Kconfig selection of hugetlbfs support 2009-10-30 15:03:54 +11:00
Kconfig.binfmt
libfs.c libfs: return error code on failed attr set 2009-09-24 07:47:30 -04:00
locks.c const: make lock_manager_operations const 2009-09-22 07:17:25 -07:00
Makefile
mbcache.c
mpage.c
namei.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 2009-09-11 08:55:49 -07:00
namespace.c fs: fix overflow in sys_mount() for in-kernel calls 2009-09-24 08:40:15 -04:00
nfsctl.c
no-block.c
open.c fs: change sys_truncate length parameter type 2009-09-23 09:21:05 -07:00
pipe.c fs: pipe.c null pointer dereference 2009-10-22 08:11:44 +09:00
pnode.c
pnode.h
posix_acl.c
read_write.c vfs: remove redundant position check in do_sendfile 2009-09-24 07:47:34 -04:00
read_write.h
readdir.c
select.c headers: remove sched.h from poll.h 2009-10-04 15:05:10 -07:00
seq_file.c vfs: seq_file: add helpers for data filling 2009-09-24 07:47:35 -04:00
signalfd.c
splice.c Merge branch 'for-2.6.32' of git://git.kernel.dk/linux-2.6-block 2009-09-14 17:55:15 -07:00
stack.c
stat.c
super.c freeze_bdev: grab active reference to frozen superblocks 2009-09-24 07:47:41 -04:00
sync.c fs/buffer.c: clean up EXPORT* macros 2009-09-23 07:39:29 -07:00
timerfd.c
utimes.c
xattr_acl.c
xattr.c VFS: Factor out part of vfs_setxattr so it can be called from the SELinux hook for inode_setsecctx. 2009-09-10 10:11:22 +10:00